Core 9001 is the clinical bone marrow transplantation unit for the Program Project. It is a resource to the program as a whole and the success of many of the projects depend upon a carefully studied group of patients undergoing marrow transplantation. The procurement of human blood, marrow, and other tissue samples (e.g. skin biopsies) for projects #1, 4 and 7 is coordinated in a timely fashion by the personnel of Core 9001. Complete clinical information is abstracted and available on all donors and transplant patients. The Core 9001 personnel are responsible for all clinical research activities and ensuring a consistent and reliable evaluation of patient outcomes including graft versus host disease and other transplant related toxicities. The Core 9001 component thereby provides a unique clinical data set that can be correlated with the results of the laboratory science studies in the various projects. In addition, the Core 9001 personnel have a strong intellectual interaction with the basic research investigators. This interaction results from both weekly joint meetings and the fact that the majority of the investigators for the projects serve as attending physicians on the transplant unit.